Pull rod slip clamp



June 14, 1932. R Q DUBUN I 1,862,886

PULL ROD SLIP CLAMP Filed Jan. 50, l95l T F[:E l

IN V EN TOR.

A TTORNEY.

Patented June 14, 1932 ATENT Fit,

REAG'AN C. DUBLIN, F WICHITA FALLS, TEXAS, ASSIG-NOR OF ONE-HALF TOUNDER- WOOD DRILLENG COMPANY, OF WIGHITA FALLS, TEXAS PULL ROD Sm CLAMPApplication January 30, 1931. Serial No. 512,324.

l his invention relates to machine elements andL particularly to pullrod slip clamps for well pumping jacks and the principal Ob ect of theinvention resides in the provision of a durable, practical and whollyefficient device capable of ready attachment to a pull rod whereby saidrod may be conveniently secured to a moving element, such, for instanceas the reciprocating element of a well pumping jack.

Another and equally as important ob ect of the invention resides in adevice of the character specified in which is contained cooperatinggripping elements, whlch are adapted to engage the smooth surface of acylindrical object, such as a pumping jack pull rod in such manner thatincreased strain upon the rod will increase the tension of the grippingelements and will thereby prevent any possible release of the devicefrom the pull rod, such as has been experienced in the use of otherdevices dependent upon. threads for rigid connection. Moreover, theselast named devices have proven impractical, due to the fact thatthreads, after having become worn or covered with rust are likely tostrip or break and release the rod, which may result in considerableloss of time in re-assembling the pull rod line.

With the foregoing objects as paramount, the invention has particularreference to its salient features of construction and arrange ment ofparts which will become manifest as the description proceeds, taken inconnection with the accompanying drawing, wherein:

Figure 1 is a side elevational view of a pumping jack, showing theposition of the invention relative thereto.

Figure 2 is a plan view of a device embodying the present inventlon.

Fi ure 3 is a side elevation of the device shown in Figure 2.

Figure 4 is a fragmentary sectional view of the casing and slips andfurther showing the safety key used in connection therewith.

Figure 5 is a detail view of the slips, and

Figure 6 is a detail view of the safety key.

In continuing further, it may be stated that the invention isparticularly adapted for use in connection with oil well pumping jacks,forming the connection between the opera tive elements of the jack andthe pull rod or power line, whereby the sucker rod assembly in the wellmay be reciprocated, to produce the desired pumping action. Although itis adapted for such use, the invention is not intended to be so limited,it being apparcut that the invention affords a very desirable attachmentin any case requiring such connection as set out in the precedingstatement.

Accordingly, 1 designates a frame of a conventional well pumping jack.The element 2, pivoted at a imparts movement to the beams 3 through themedium of rods 4. The beams being connected to the sucker rod assembly5, the latter is reciprocated for the required pumping action.

Theforegoing briefly describes the conventional ack in order that theinvention and its purposes will be better understood. It will be notedin Figure 1 that the power line or pull rod assembly 6 connects with therocking element 2 and conventional devices by which this connection isestablished have been found to be wanting in strength and 'durabilityandusually does not resist the ex 'cessive strain imposed upon them from aview point of economy and practicability.

The invention 1s comprised of a housing shown 1n Figures 2 and 8, whichhas parallel portions 7 which areconnected by means of a bolt 8 to alink 9, or its equivalent, which latter engages the element to beoperated by the pull. rod'assembly, and in the present case. to aportion of the rocking member 2 of the conventional jack shown inFigure 1. The housing previously mentioned is a unitary structure and isfurther provided with a reduced portion a having a conical interior andexterior surface.

"The fact that the end of the housing has the conical reduced portion ata is of great importance in that it is within this reduced portion thatthe sleeves or gripping elements are container, which, when combined arealso coniform, as apparent in the several figures, although they are intwo or more see- 2 1,se2,sse

tions, which may be determined by reference to Figures 4 and 5. There isprovided on one of the slip sections an integral projection 11, whichcorresponds with a recess 12 in the other setcion, although the saidrecess is of such width as to loosely receive the said projection 11.The purpose of this recess and projection is to allow slight slippage ofthe slips 10 independently, but to limit this slippage to only therequired degree. In fact, the arrangement merely knocks the slipsloosely together in their relationship shown in Figure 1.

The slips 10, as apparent particularly in Figures 4 and 5 are knurled orthreaded on their inner surfaces at b, to better grip the ends of acylindrical object or a rod which they surround and in the relationshipshown in Figure 4, it is apparent that any efiort to withdraw the rod (3from its position shown, will result in tightening the gripping efiectof the slips and in fact, the gripping action of the slips will beincreased in proportion to the strain on the rod 6 and will positivelyhold the latter against displacement. While the rod 6 is shown inFigures 2 and 3 as having an enlargement 13 upon its inner end, Figure 4shows the rod having a smooth end, it being pointed out that in extremecases, the enlargement 13 may be practicable but not wholly necessaryand is applied only as a precaution against accident.

As a further precaution, a safety key 14 is inserted in slots 15 in thecasing and, as apparent in the Figures, has a fiat side and a taperedside, the former affording a surface against which the enlargement 18,or the end of the rod 6 may project. As shown in dotted lines in Figure6, the bifurcated end may be turned outward to positively hold the keyagainst accidental displacement from its 0perative position.

In assembling the invention. the connec- .ion is made between the casingof the invention and the link 9 through the medium of the bolt 8 andafter having so connected the cas ing, the cotter pin 16 is inserted, asshown in Figures 3, to hold the bolt 8 in position. The end of the rod 6is then inserted into the reduced end a of the casing and the slips 10are inserted in the space between the parallel arms 7 and moved into theconical reduced portion of the casing in interlocked relationship. Afterhis, the key 14: is inserted and locked, whereupon the device is incondition for operation. However, in some instances, especially when thehead 13 is provided on the rod 6, it is desirable to apply the connectorbefore joining the latter to the element which is required to bereciprocated, such for instance as the link 9. In this connection it maybe mentioned that the mode of application has no bearing on theinvention whatsoever.

Manifestly, the construction shown is capable of some modification andsuch modification as is considered Within the scope and meaning of theappended claim is also considered within the spirit and intent of theinvention.

What is claimed is:

In a pull rod slip clamp, a combination including a body having a pairof parallel arms integral therewith and perforated to receive a bolt,said body being swaged into conical shape at one end and havingdiametrically opposed slots at a point immediately forward of saidconical end, trunco-coniform slips arranged to conform within theconical end of said body and capable of limited relative slidablemovement and having roughened inner surfaces to engage and hold a rodand a wedge receivable in the slots in said bodyto prevent displacementof said slips.

In testimony whereof I afiix my signature.

REAGAN C. DUBLIN.

